1. Field of the Invention
The present invention relates, in general, to vehicle seats and, more specifically, to power seat adjusters for vehicle seats.
1. Description of the Art
Power seat adjusters are available on many automotive vehicles. Such power seat adjusters are primarily used on the driver's seat and, occasionally, also on the front passenger seat of the vehicle.
Power seat adjusters typically carry an upper support frame or support members which engage and support the seat bottom of a vehicle seat. The upper support members are mounted on first and second, spaced track assemblies, each formed of an upper track which is connected to the upper support members and which is also slidably mounted in a lower track anchored to the vehicle floor. A drive mechanism, typically formed of a bi-directional electric motor mounted on the power seat adjuster, rotates a pair of drive shafts extending outward from the motor to a gear assembly or gear box mounted in each upper track. In one arrangement, the gear box rotates a lead screw extending along each upper track. A drive block connected by a bracket extending outward from the upper track and downward to a fixed connection with the lower track threadingly receives the lead screw to cause reciprocal movement of the upper track and the attached upper support member upon selective direction energization of the drive motor. Other drive motors may also be incorporated into the power seat adjuster to provide vertical movement of the front or back or both ends of the upper support members as well as pivotal movement of the seat back with respect to the seat bottom.
In certain vehicle configurations, interior space for mounting a vehicle seat having a power seat adjuster is constricted or limited, particularly in height. Such vehicle configurations have previously required a manual seat adjuster due to the larger height requirement of power seat adjusters employing electric drive motors and interconnecting drive shafts, links, lead screws, etc. This is particularly the case in power seat adjusters having a bracket attached to a drive nut mounted on a lead screw in an upper track which extends outward from the upper track and then downward to a fixed engagement at one end to the lower track.
Thus, it will be desirable to provide a power seat adjuster for a vehicle seat which has a minimal height so as to be usable in a wide variety of vehicle configurations. It would also be desirable to provide a power seat adjuster having at least horizontal fore and aft movement which has improved mechanical response and a reduced cost compared to previously devised power seat adjusters.